You can also add a superclass using drag-and-drop:
- Select Editor in the Class Browser.
- Hold down the mouse button and drag the Editor class over Employee. Employee is outlined.
- Before releasing the mouse button, hold down the Ctrl key, then release the mouse button to drop the subclass.
To remove a superclass from a class, highlight the superclass you want to remove in the Superclasses pane and click the
Remove Superclass 
button. You are now ready to assign some attributes to the classes you have created, by creating
slots, which are covered in the next section.